Complete suspension rebuild

Topic: Complete suspension rebuild - Advice needed (Read 6737 times) previous topic - next topic

Complete suspension rebuild - Advice needed

December 18, 2016, 11:11:47 AM

I'm planing on redoing the entire suspension on the Cougar this winter and would like some advice on how to proceed. We previously had a one car garage and my wife's Volt got to be inside so it could charge but we just built a new house with a three car garage so the Cougar has a dedicated spot and I can take my time with this project.

Here is a quick rundown of the car so far. It is an 86 Cougar that was originally a 5.0/AOD car and now has a 2.3T/T5. The following parts on it are from an 87 TC parts car; spindles, steering rack, brakes, struts, shocks, rear axle, springs, and sway bars.

I had it aligned after I swapped all he suspension stuff but have never really been happy with the outcome. The car has some positive camber and wears out the outer edge of the tires faster than normal. It also feels floaty and the steering feels off. I don't drive the car often so I've tolerated it but it's time to fix it.

I'd like crisp handling but it doesn't have to be road race worthy. I only drive it once or twice a month so I can deal with a bit less comfort than normal if necessary.

I plan to replace shocks, struts, ball joints, control arm and sway bar bushings, and tie rod ends. I would like to lower it an inch or two also. I also plan to get some new 4 lug 17x9 wheels. What else should I look into replacing? I'm leaning toward factory style replacement but will upgrade if the price/benefits are right.

Any advice is appreciated.

Complete suspension rebuild - Advice needed

Reply #1 – December 19, 2016, 07:30:03 AM

I used 1999 Mustang springs in mine to lower it about two inches yet retain a great ride quality. I didn't want the car bouncing around on every bump, and still want to be able to manage a speed bump easily.

I'm rebuilding the entire suspension on the Sport this spring. Poly bushings, replace the rack, lower control arms, .....everything.

Complete suspension rebuild - Advice needed

Reply #2 – December 19, 2016, 09:42:42 AM

With the 2.3L over the nose of the car the only way I know to lower the front would be coil overs (costly), maybe a set of new springs for the SVO Mustangs, or cutting a new set of stock springs. I cut a set back in the day for my 85 TC and the only real disadvantage I can tell you is it may take several times to get the ride height you want. I would start with half a coil and see what that does and then continue tpuppies until you get the height you want. For the rear do what Vinnie said and get a set of the SN95 rear springs and I would ask Vinnie what model his came out of (V6, V8, Mach 1, Cobra, convertible) as they have different rates.

To really see how the car will lower I would install the rear springs first and get it back on the ground. Next remove the front springs and then reassemble the front suspension without the springs and lower the front down with the aid of a hydraulic jack to get the front at the height you want it to match the rear. You may notice that as you lower the front the rear height changes as the chassis is loaded. This will give you an idea as to whether or not the rear springs you have are going to get you the drop you want or not. This would just be how I would do it but if I were a betting man I would get in touch with Chuck and see what he recommends as his car has what I consider a perfect stance.

As for the dampers, I cannot stress how important these are to the overall car itself. With you having a 2.3L up front the typical use of the V8 Fox or SN95 Mustang struts may not be the best solution. I would look and see if anyone makes really good struts for the Fox SVO mustang as that would be the way to go being you are wanting to drop the car an inch or so. I would do the same for the rear of the car and snag Vinnie's Chuck W adapters for the rear Fox Mustang shocks.

I am not a fan of poly or urethane bushings in stock control arms. They created a very harsh ride in my 85 TC so I pulled it all back apart and installed MOOG replacement rubber bushings and it was like night and day difference. I would strongly suggest getting a set of CHE (https://www.cheperformance.com/collections/83-88-thunderbird-and-cougar-parts) UCA's and LCA's for the rear of the car if you do not already have them and get the adjustable uppers so you can dial in the pinion angle after lowering the car and you can also get the ride height adjustable lowers.

If you are going to get a new rack and pinion for the car I would suggest the SN95 Mustang rack with the Maximum Motorsports hybrid steering shaft adapter (http://www.maximummotorsports.com/Steering-Shaft-Assembly-SN95-Power-Steering-Rack-1979-93-Mustang-P461.aspx). You will need to use Fox inner tie rod ends so that you can use the Fox outer tie rod ends (SAE threads and shorter than the SN95 stuff). This would be to get a better road feel in the steering wheel. The Fox racks are too boosted in my opinion (has to do with the T bar) and the SN95 racks give you a lot more feedback through effort in turning the wheel. If you are happy with how yours feels then swap back out with a Fox rack and be done with it.

Last comment I have would be to get a set of the Maximum Motorsports caster/camber plates (http://www.maximummotorsports.com/1983-1988-Thunderbird-C682.aspx) and that should solve your tire wear issues and help with aligning the front end with it lowered.

Complete suspension rebuild - Advice needed

Reply #3 – December 19, 2016, 09:58:03 AM

For rear control arms go with these: http://www.maximummotorsports.com/Extreme-Duty-Adjustable-Rear-lower-Control-Arms-1983-1989-Thunderbird-P1444.aspx

I've got them with the stock upper arm with new rubber bushings. The ride is nice and controlled with no harshness. These arms let the suspension articulate properly without binding. Plus you can adjust the ride height to what ever you want.

Whatever you do up front don't use poly bushings. Go with rubber. It'll ride and handle fine without beating you to death like poly bushings will.

Complete suspension rebuild - Advice needed

Reply #4 – December 19, 2016, 11:20:35 AM

X2 on the MM lowers if you have the $$. I have MM's entire suspension on my Coupe and it is awesome. The CHE stuff is good and very affordable however I firmly believe the MM stuff is a notch above it.

One other thing I thought about was sub frame connectors. There are several DIY threads on them here and if you can weld very easily done. If you are not a welder then I would suggest the Global West units (http://www.globalwest.net/1980-88thunderbird.html) as they are fantastic units. I have them on both the Coupe and the Bird and they actually made the cars ride smoother and handle loads better.

Complete suspension rebuild - Advice needed

Reply #5 – December 19, 2016, 11:42:52 PM

X2 on the caster camber plates!

Complete suspension rebuild - Advice needed

Reply #6 – December 20, 2016, 12:06:18 PM

The suspension set up on my car was put together almost 20 years ago. I would probably do things a little differently these days (and I may, if I get inspired to do so).

My front springs are the Motorsport C-Kits. (B-kit springs suck) 650# linear rate. There is a small spacer (1/8") at the top between the isolator and the body. The rears are SN-95 V8 convertible springs. The RLCA mounting point on the rear axle is lowered about 3/4" (I worked at Kenny Brown---it's what we did). That is the only bit of lowering for the rear(and has other benefits). I used this exact set up on at least 3 Fox cars with the same excellent results.

I made my own (very) aggressive CC plates and altered the LCA mounting points on the front of the car. These didn't affect the height, but did increase front grip and the car has almost no dive under braking.

If you can find the C-Kits, those are my suggestion over SN-95 front springs (Unless you're going coil-over). The C-Kit rears are way too short and light for the heavy ass end of the TBirds/Cougars, even though they have a higher spring rate. Avoid B-Kits like the plague.

Complete suspension rebuild - Advice needed

Reply #7 – December 21, 2016, 03:23:51 PM

So being that you do not work at KB any longer and I am assuming any rights they had to the knowledge with regards to these cars has long passed...care to explain the advantage(s) of dropping the LCA mount location on the rear end?

Complete suspension rebuild - Advice needed

Reply #8 – December 21, 2016, 07:00:10 PM

Quote from: Aerocoupe;458587

So being that you do not work at KB any longer and I am assuming any rights they had to the knowledge with regards to these cars has long passed...care to explain the advantage(s) of dropping the LCA mount location on the rear end?

It was a thing that they did on the Fox cars. The TracKit (and TracKit Plus) lowered the LCA mounting point to increase anti-squat under launch and it also helped with anti-dive under braking. (What they call them now)

Any Fox TBird knowledge came and left with me. They never wanted to hassle with it, but I got them to do a few things.

If someone doesn't want to lower that point. A set of RLCAs with an adjustable spring perch or cutting a little off the spring will drop the rear. You won't get the geometry benefits though.

Complete suspension rebuild - Advice needed

Reply #9 – December 21, 2016, 08:33:21 PM

Thanks for the great responses guys!

I guess I should have added that this car is somewhat of a budget build. The parts cars I used to build it were $200 and $450. The most expensive part I've bought so far was a $250 used A237 cam.

The main reason I want to lower the car is because it sits higher than stock. I think it's probably because I've taken a bunch of weight out of the car. It's mostly gutted and weighs in at 2920. I'd really just like it a tad lower than stock. Like Vinnie said, I'd like to not worry about speed bumps.

I've noticed that SN95 springs seem to all be linear and my current TC springs are progressive rate. Is it OK to cut my current springs or are different springs going to be needed for sure?

I have a welder and can weld (at least on parts of the car people won't be seeing...) so subframe connectors are a great idea. I'll dig up some threads to see what others have done.

I'm planning on keeping the current steering rack in the car as it doesn't have any noticeable slop and doesn't leak.

I'll do some research over on NATO to see what they use for struts/shocks.

Are the caster camber plates necessary even with as stockish of a setup as I have? Is it possible that the person who aligned it just botched it?

Does anybody have any experience doing alignments at home?

Should I go with with rubber bushings all around if I don't upgrade the control arms?

Sorry for all the questions and thanks again for the responses.

Complete suspension rebuild - Advice needed

Reply #10 – December 21, 2016, 10:23:11 PM

CC plates aren't required, but they make it easier when you lower the car. There is only so much adjustment in the stock mounts. Also, adding a bit of positive caster improves handling and tire wear.

I do all of my alignments at home. Lots of ways to do it.

SFC's are a good idea on any Fox that you plan on driving. I've cracked a windshield in a Cougar due to body flex.

Complete suspension rebuild - Advice needed

Reply #11 – December 22, 2016, 12:31:36 AM

When I lowered my car, I didnt originally have caster/camber plates and I started to eat up the inside of my tires cuz they were negative camber'ed in.

Complete suspension rebuild - Advice needed

Reply #12 – December 22, 2016, 10:12:58 AM

My '83 at stock height would weart the inside of the front tires but it was not anything terrible just an issue. The car was bone stock and all of the factory adjustment was used. I went to a alignment shop that was recommend by a buddy that I considered all knowing in things of cars at that time in my life (I was 18 or so) and they installed smaller diameter strut bolts in the top holes which allowed them to gain just enough camber to stop the wear issue. This is something that can be done but the bolt could slip over time.

My suggestion would be to suck it up and buy the CC plates and drop the car down so it handles. Your only cost will be the CC plates, a set of used rear springs out of a convertible SN95 Mustang, and a properly cut set of front springs. I would also look at the LCA axle mount hole relocation as Chuck suggested as that sounds like a freebie that none of us should pass up.

If you are keeping all of the original control arms in the rear then replace all of the bushings with rubber and I would do the same on the front control arms. The stock rear control arms are pretty flimsy so my suggestion would be to box them (both uppers and lowers) with the old bushings in them. This will aid in pressing the old bushings out and installing them new ones.

Complete suspension rebuild - Advice needed

Reply #13 – December 22, 2016, 10:22:34 AM

Found some pictures of what I am talking about on the Corral and just stole them for reference here as the Corral is so loaded with adds now it sucks to get on that site.

Complete suspension rebuild - Advice needed

Reply #14 – December 22, 2016, 10:24:11 AM

And one more. You can see why you want to weld these up prior to changing the bushings as all the heat is probably no bueno for them.